Within the scope of the LU Visualisierung at the ICGA we implemented a flow visualisation tool. This means that an image is generated without any geometric primitives. A large dataset that contains information about - let's say - a river delivers the whole information about the picture. On the one hand this tool can draw an arrowplot and on the other hand it draws a streamlines.

The task was ..

1) .. to draw an arrowplot

2) .. to draw evenly spaced streamlines

3) .. to color the additional parameters (pressure and vorticity)

4) .. develop an application with a lot of interaction possibilities

5) .. to achieve significant images

- Arrowplot: texturized arrows and untexturized arrows

- streamlines calculated by Euler Integration and Runge Kutta 2 Integration

- control over density and size

- editable Transferfunctions for pressure and vorticity

- different Vector interpolation types

- Tapering

- Texture generation

The program provides an easy way to edit the mapping for pressure and vorticity values in the flow data. Two independent Dialogs implemtent this functionality (see below).

It is also possible to load and store the current state of the transfer function to ease the handling.

Transfer Function

with a loaded color mapping

Below you can see some sample images genrated by our application. Due to demonstration issues we have tried to vary the parameters as much as possible.

Density = 9.1%
Arrowlength = 65.1%
untextured arrows
arrows are not equallized

Density = 9.1%
Arrowlength = 65.1%
textured arrows
arrows are not equallized

Density = 6.2%
Arrowlength = 92.2%
untextured arrows
arrows are equallized

Density = 6.2%
Arrowlength = 92.2%
textured arrows
arrows are equallized

different Transferfunctions

different Transferfunctions

The following section gives you an overview about the streamlines this application can do. The difference between images with tapering and images without tapering; differences in the kind of integration and differences in the kind of interpolation are illustrated.

Density = 3.5%
DSep = 44.1%
DT = 68.3%
without Tapering

Density = 3.5%
DSep = 44.1%
DT = 68.3%
with Tapering

Density = 2.5%
DSep = 44.1%
DT = 68.3%
Euler Integration

Density = 2.5%
DSep = 44.1%
DT = 68.3%
Runge Kutta 2 Integration

Density = 2.5%
DSep = 50%
DT = 67.1%
Runge Kutta 2 Integration

Density = 2.5%
DSep = 98.4%
DT = 67.1%
Runge Kutta 2 Integration